In flat-panel display (FPD) technology, the display effect of the whole display device is related to a great extent to the uniformity of the light emitted by the backlight unit. Direct-lit type backlight unit is widely used in display devices and the diffuser plate is a key component of the entire direct-lit type backlight unit.
FIG. 1 schematically illustrates a configuration of a diffuser plated as included in a conventional backlight unit.
The diffuser plate included in the conventional direct-lit type backlight unit generally comprises a plate-shaped substrate 02. A diffuser film 01 is disposed on a side of the substrate 02 that faces a light source of the backlight unit (i.e., light incident side of the diffuser plate) and a scattering particle film layer 03 is disposed on the opposite side (i.e., light emission side of the diffuser plate).
The light emitted by the light source is scattered by the diffuser film 01 and the scattering particle film layer 03. Conventionally, the diffuser plate of the direct-lit type backlight unit scatters the light beam from the light source homogenously without distinguishing positions of a luminophor and a non-luminophor. However, in the direct-lit type backlight unit, the luminophors in the light source are arranged with a certain space between each other and the positions having the luminophors have a higher brightness than the other positions. As a result, the light can not be scattered sufficiently enough when passing through the diffuser plate 01 and the scattering particle film layer 03, which will cause the phenomenon of luminophor-located positions having higher brightness than the other positions. Such a phenomenon can further produce an uneven brightness and Lamp Mura and negatively affect the display quality of the products.